CVE-2026-42582

Summary

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final, when decoding header blocks, the non-Huffman branch of io.netty.handler.codec.http3.QpackDecoder#decodeHuffmanEncodedLiteral may execute new byte[length] for a string literal before verifying that length bytes are actually present in the compressed field section. The wire encoding allows a very large length to be expressed in few bytes. There is no check that length <= in.readableBytes() before new byte[length]. This vulnerability is fixed in 4.2.13.Final.

Affected Software

VendorProductVersion RangeStatus
nettynetty>= 4.2.0.Alpha1, < 4.2.13.Finalaffected
io.nettynetty-codec-http3>= 4.2.0.Alpha1, < 4.2.13.Finalaffected

Weaknesses

  • CWE-770: CWE-770: Allocation of Resources Without Limits or Throttling
  • CWE-789: CWE-789: Memory Allocation with Excessive Size Value

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: yes
    • Technical Impact: partial

Additional References

References